In radiation dosimetry there are numerous problems associated with the measurement of isodose curves and depth-dose distributions in high-gradient regions of beams using conventional measuring systems such as ionization chambers, semiconductors, thermoluminescent detectors (TLDs), and radiographic films. The evaluation of an ionizing photon beam is difficult by using silver-halide radiographic film, because of large differences in sensitivity to photon energies in the 10-200 keV region, even though its relatively high spatial resolution offers an advantage over most other radiation measuring systems. Energy absorption and transfer properties of radiographic films do not match those of biological tissues. Radiographic films also have the disadvantages of being sensitive to room light and requiring wet chemical processing.
The radiation sensitivity of the Radio-chromic Nylon Dosimetry Film System FWT-60-00 has been studied as a function of relative humidity of the air with which it is equilibrated. Data is presented for several temperatures and relative humidities of 20%-80%. The prior art results of the studies indicate a very low dependence on humidity over the range of 30% to 70% relative humidity with decreasing sensitivity at both lower and higher humidities.
Radiation dosimeters currently lack a high spatial resolution, absolute value of the absorbed dose, wet processing, environmental instability, and difficult data handling.